Test if c is a valid UTF-32 character.
\uFFFE and \uFFFF are considered valid by this function, as they are permitted for internal use by an application, but they are not allowed for interchange by the Unicode standard.
true if it is, false if not.
See Implementation
Test if c is a valid UTF-32 character.
\uFFFE and \uFFFF are considered valid by this function, as they are permitted for internal use by an application, but they are not allowed for interchange by the Unicode standard.